Associations between EEG measures and clinical severity in CDKL5 deficiency disorder.

OBJECTIVE: Prior work has shown that quantitative EEG and evoked potentials (EPs) may be useful as objective measures of brain function for CDKL5 deficiency disorder (CDD), a developmental and epileptic encephalopathy associated with pathogenic variants in CDKL5. The current study builds on this work by examining associations between EEG/EP parameters and CDD-specific symptom severity in a large, representative cohort of individuals with CDD. METHODS: Resting EEG and visual and auditory EPs were acquired from 77 participants with CDD in a multi-site study designed to enhance clinical trial readiness for CDD. The statistical analysis evaluated associations between the EEG/EP parameters and validated CDD-specific measures of clinical severity. RESULTS: Resting EEG 1/f slope and power ratios were significantly associated with the clinical measures such that greater EEG background slowing correlated with greater symptom severity. In contrast, neither visual nor auditory EP measures were significantly associated with clinical severity in this cohort. CONCLUSIONS: The results underscore the potential utility of resting EEG parameters to serve as objective measures of clinical severity and brain function for CDD. SIGNIFICANCE: Future studies should continue to refine resting EEG as a biomarker to facilitate therapeutic development for CDD, as well as test new methods for the acquisition and analysis of EPs in this population.